Referring to FIG. 12, a conventional paper shearing apparatus 1 is shown. The paper shearing apparatus 1 includes a platform 2, a first knife 5 secured to a side of the platform 2 and a second knife 3 pivotally attached to the side of the platform 2 in order to cooperate with the first knife 5 as a pair of shears. In use, the second knife 3 is lifted from the first knife 5. A sheet 4 is put between the first knife 5 and the second knife 3. A first portion of the sheet 4 is put on the platform 2 and a second portion of the sheet 4 is located beyond the platform 2. The second knife 5 is pivoted toward and past the first knife 3, thus shearing the second portion of the sheet 4 from the first portion of the sheet 4. It is desired that a straight edge is formed of the first portion of the sheet 4 and a straight edge is formed of the second portion of the sheet 4 because of the shearing. The sheet 4 is, however, always deformed during the shearing, thus forming a curved edge of the first portion of the sheet 4 and a curved edge of the second portion of the sheet 4. In addition, the second knife 3 is intended to pivot in a plane in which the first knife 5 is located in order to shear. The second knife 3 is however biased from that imaginary plane during the shearing and particularly so when cutting a stack of sheets or a thick sheet.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.